Toxicological Profile of Ultrapure 2,2′,3,4,4′,5,5′-Heptachlorbiphenyl (PCB 180) in Adult Rats
Figure 7
Microphotographs of the thyroid gland of female rats and BMD analysis of follicle depletion.
Decrease of follicle contents is illustrated by comparing samples from controls (A) and 300 mg/kg bw (B). BMD analysis of follicle depletion (measured as the estimated area with large follicles on representative sections at low power magnification) indicated that this effect was dose-dependent (C). Small circles indicate individual samples, large circles group means; the vertical dotted line indicates the dose (CED) with 5% decrease (CES -0.05) compared to background (a parameter). The thyroid glands also showed follicle epithelium hypertrophy as illustrated by comparing 10 (D) and 300 mg/kg bw (E). Epithelium cell height is indicated by bars at basal and apical cell borders.